Frank - HK-Dac/Arcam Black box - enstein

[blistard]

Can somebody here give me some insight on the following?

Is it possible to take an HK-dac (lampucera) en connect the output of the DAC to the output-section of my Arcam Delta Black Box 3.
My idea is to take the output a C27 and C33 of the HK-dac and feed it (through a coupling condensator) to SK5 on the Arcam board.
I also want to feed the HK-dac the 5V from the Arcam.

Is all this possible, or is my lack of knowledge shining through here?

 

[amc184]

No.

The DAC that the Black Box uses (a TDA1541A) and the DAC that the Lampucera (a CS4397) have completely different analog outputs. The TDA1541A has single ended current outputs, the CS4397 has balanced voltage outputs. This means that the output stage in the Black Box is totally unsuitable for use with the Lampucera.

Why were you wanting to do this? Is the Black Box broken?

 

[blistard]

Thanks for the answer.
The Black box, I own is not the version with the TDA 1541, but the 1543 bitstream version ( BB3 ). And indeed, it is broken.
Looking at the schematic of the BB3 I thought there might be an I/V stage on the digital board, before the signal is transferred to the analog/output board. But again, I am no eletronics-wizz.

thanks again

 

[amc184]

I'm sorry, I was thinking that the Black Box 1, 2 and 3 are more or less the same, but it's just 1 and 2, the 3 being quite different.

The differential to single ended conversion is carried out on the DAC board. It should be suitable to hook up to your Lampucera, but with the following issues:

- The output stage is single ended, you can just use the L+ and R+ outputs of the Lampucera, but you will lose about 6dB of SNR.

- The output stage is DC coupled with a servo. If the voltage offset of the new DAC is higher than the old one the servo may no longer work properly.

By the way, the Black Box 3 uses two SAA7321a, not a TDA1543.

 

[blistard]

Thanks,

Is it not necessary to use an condensator between the lampucera and the BB3?

 

[blistard]

Hello All,

I've got the DAC as described in http://www.diyaudio.com/forums/digital-line-level/137976-experience-diy-dac.html (and it works, I made something! ) and I wan´t to try using the opamp-stage of my BlackBox3.
I want to connect the L+ and the R+ (single-ended) to the input of the analoge-board. Do I need to connect a "0" between the 2 boards? What "0" of the Hongkong DAC should I use for this? The 0 from the 12-0-12 transformer?

 

[blistard]

It's alive!
I simply used the signal from L- and R- and connected it to the Black Box using some USB-motherboard-headerthingy I had laying around. It ain't pretty but it lives.
I guess a "how to mod your BB3" is not very usefull, but to anyone owning this DAC I can recommend this mod. (not to be used on Black Box 1 and 2 for obvious reasons)

 

[blistard]

This seems to become a 1 person thread, but I hope someone can help me answer this questions:

I want the HKdac to power the relais of the Black Box. The BB relais needs 5 volt.
Does the HKdac relais switch on digital lock?
Does the HKdac relais use 5 volt?
Is the polarity important for a relais?

thanks